<h2>Answer: Light waves have a redshift due to the Doppler effect
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The astronomer Edwin Powell Hubble observed several celestial bodies, and when obtaining the spectra of distant galaxies he observed the spectral lines were displaced towards the red (red shift), whereas the nearby galaxies showed a spectrum displaced to the blue.
From there, Hubble deduced that the farther the galaxy is, the more redshifted it is in its spectrum. <u>The same happens with the stars and this phenomenom is known as the Doppler effect.
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This phenomenon refers to the change in a wave perceived frequency (or wavelength=color) when the emitter of the waves, and the receiver (or observer in the case of light) move relative to each other. For example, as a star moves away from the Earth, its espectrum turns towards the red.
Parallel circuit
Advandages: 1. Every unit that is connected in a parallel circuit gets equal amount of voltage.
2. It becomes easy to connect or disconnect a new element without affecting the working of other elements.
3. If any fault happened to the circuit, then also the current is able to pass through the circuit through different paths.
Disadvantages: 1. It requires the use of lot of wires.
2. We cannot increase or multiply the voltage in a parallel circuit.
3. Parallel connection fails at the time when it is required to pass exactly same amount of current through the units.
series circuit
Advantages: 1. Series circuits do not overheat easily. This makes them very useful in the case of something that might be around a potentially flammable source, like dry plants or cloth.
2. Series circuits are easy to learn and to make. Their simple design is easy to understand, and this means that it’s simple to conduct repairs .
3. we can add more power devices, they have a higher output in terms of voltage .
4. The current that flows in a series circuit has to flow through every component in the circuit. Therefore, all of the components in a series connection carry the same current.
Disadvantages: 1.If one point breaks in the series circuit,the total circuit will break.
2. As the number of components in a circuit increases ,greater will be the circuit resistance.
(E=mc^2)
<h3>
<u>Where</u><u>:</u></h3>
<u>m</u><u> </u><u>is mass</u>
<u>And c is a constant for speed of light</u>
M*g*sin20-f=m*a
<span>and the rotational frame </span>
<span>f*r=I*a/r </span>
<span>where f is the force of friction, a is the translational acceleration and I is the moment of inertia of the sphere </span>
<span>combine and solve for f </span>
<span>a=g*sin20-f/m </span>
<span>and </span>
<span>f*r^2/I=g*sin20-f/m </span>
<span>or </span>
<span>f=g*sin20/(r^2/I+1/m) </span>
<span>I=2*m*r^2/5 </span>
<span>therefore </span>
<span>f=2*m*g*sin20/7</span>
